The top general in Thailand's ruling junta warned people not to join anti-coup street protests on Sunday, saying normal democratic principles cannot be applied at this time, as troops fanned out in central Bangkok to prevent rallies.

Gen. Prayuth Chan-ocha also defended the detentions of dozens of politicians and activists, most of them associated with the ousted government, with a spokesman quoting him as saying that the measure would not last more than a week and was allowed by law.

In a chilling move apparently aimed at neutralizing critics and potential opposition, the junta has also ordered dozens of outspoken activists, academics and journalists to surrender themselves to military authorities, including a prominent Thai reporter.

Pravit Rojanaphruk, an outspoken columnist for the English-language daily The Nation, tweeted that he was reporting to the junta: "On my way to see the new dictator of Thailand. Hopefully the last," he wrote.

The military, which is already holding most of the Cabinet in secret locations after Thursday's coup, said it would keep former prime minister Yingluck Shinawatra and others in custody for up to a week to give them "time to think" and keep the country calm.

Starting Monday, those in detention who have arrest warrants or face criminal charges will be handed over for prosecution, said deputy military spokesman Col. Winthai Suvaree.

Anti-coup protests

He also said that the general "urged every group of citizens to avoid joining the anti-coup protests because at the moment, the democratic principles cannot be executed normally."

In the three days since Thailand's first coup in eight years, the junta has faced scattered protests amid growing concern over its intentions. Troops were deployed in central Bangkok's main shopping district on Sunday in a bid to stop any gatherings.

However, more than 1,000 protesters shouting anti-coup slogans defied the military's warnings and marched across the capital. It was the largest expression of dissent since the army seized power last week after months of political turmoil.

On Saturday, the military dissolved the Senate - the last functioning democratic institution left, and absorbed its legislative powers.

To achieve compromise

More than 150 people have been held incommunicado by the military, according to rights groups. Deputy army spokesman Col. Weerachon Sukondhapatipak said they were all being treated well and the military's aim was to achieve a political compromise.

Among those academics summoned by the military was Kyoto University professor of Southeast Asian studies Pavin Chachavalpongpun. However, speaking by telephone from Japan, Pavin said he would not turn himself in.

"The military claiming to be a mediator in the Thai conflict, that is all just nonsense," said Pavin, who is frequently quoted by foreign media as an analyst. "This is not about paving the way for reform and democratization. We are really going back to the crudest form of authoritarianism."

AFP-AP